Content distribution networks are used to deliver all types of content from origin servers to client computing systems. To efficiently deliver such content, distributed cache hierarchies intervene between origin servers and client computing systems. When a client issues a request for content, if the content is available in the hierarchy, the content may often be provided by the hierarchy rather than having to obtain the content all the way from the origin server, provided that the content is found in the hierarchy.
In many cases, the cache hierarchy is partitioned in such a way that content items are cached mutually exclusively with one another, while providing a way to route the requests accordingly and expectedly to find the cached content. Therefore, when a request is routed to a cache server, the cache content is expected to be cached by that cache server and it would likely result in a cache hit, meaning the requested content is cached by that cache server and thus the cache server may satisfy the content request directly. One way to do this is to perform such cache distribution and predictive routing at the edge caching tier (in a cache hierarchy, this would be the first tier of cache servers geographically closest to the client).
A conventional way for a client to determine a location of cached content in an edge caching tier is for the client to first provide the Uniform Resource Locator (URL) of the desired content to an intelligent Domain Name Server (DNS) server. The intelligent DNS server knows the geographic proximity of the cached content, and provides an Internet Protocol (IP) address of a cache server that would perform well for the client. The client then requests the content using the IP address provided by the intelligent DNS server.